Conventionally, a shut-off valve capable of switching between a circulation state where fluid flown in from an inlet is allowed to flow out from an outlet and a shut-off state where fluid flown in from the inlet is prevented from flowing out from the outlet has been known (e.g., see Japanese Unexamined Patent Application, Publication No. 2009-92192).
The shut-off valve disclosed in Japanese Unexamined Patent Application, Publication No. 2009-92192 switches between the circulation state and the shut-off state by bringing a valve body into contact with a valve seat, or separating the valve body from the valve seat.